update sinanews
set paidcmt = foo.paidcmt
from 
(select count(distinct(cmt.uid)) as paidcmt, cmt.newsid
from sinanewscomments as cmt, (select distinct(uid)
from
(
select distinct(uid)
from knownpaidcommentators1
UNION
(select distinct(uid)
from knownpaidcommentators2)
) as foo) as fc
where cmt.uid = fc.uid
group by cmt.newsid) as foo
where sinaclick4.newsid = foo.newsid
